The Kosons are the only gold coins that have been minted by the Dacians, named after the Greek alphabet inscription "ΚΟΣΩΝ" on them. It is thought that "Koson" is the name of an otherwise historically unrecorded Dacian king, though he may be identical to the Cotison mentioned by Horace and Suetonius.
The coins contain Roman iconography: on the obverse, there is an eagle standing on a scepter and holding a wreath in their claw (inspired by the silver denarii issued by Pomponius Rufus); the reverse contains three men dressed in togas, two of them holding an axe on the shoulder (possibly inspired by the silver denarii issued by Marcus Junius Brutus in 54 BC).
Coins inscribed KOSON were discovered in several large stashes in Transylvania. The biggest group was discovered in 1543, and contained several thousands coins and objects made of gold. It was rumored that this stash was revealed in a bolted chamber under the river Strei, identified as the river Sargetia, and also mentioned by Dio Cassius. Further research disproved this, and placed the treasure in one of the Dacian castles in the Orăştie mountains, probably in Sarmisegetusa.
Debate regarding the name "Koson" was prompted after the discovery of the coins. The discovery captured the attention of writers at the time. Thus, there are comments from Erasmus of Rotterdam in 1520 and Stephanus Zamosius (István Szamosközy) in 1593.
Modern scholars agree that the name Koson most likely refers to a local king about whom nothing else is known. Vasile Pârvan argues that he was probably a Thracian dynast who employed the Dacian Getae tribe in plundering raids across the Danube, paying them in his coins. Theodor Mommsen argued that Koson was probably a Dacian ally of Brutus, since the coins seem to derive their imagery from those minted by Brutus himself. Recent scholars often argue that he is very likely to be identical to the "Cotison" mentioned by Horace (Odes III., 8, 18,) and Suetonius, (Augustus, 63.), a Dacian king during the reign of Augustus who had raided over the Danube.
- Bogdan Constantinescu et al, "Archaeometallurgical Characterization Of Ancient Gold Artifacts From Romanian Museums Using XRF, Micro-pixe And Micro-SR-XRF Methods", in Proceedings Of The Romanian Academy" Series A, Volume 13, Number 1/2012, pp. 19–26
- Erasmus, trans. R.A.B. Mynors (1988). Collected Works of Erasmus Volume 8: Letters 1122 to 1251, 1520 to 1521. Toronto: University of Toronto Press. p. 37.
- Zamosius, Stephanus (1593). Analecta lapidum vetustorum et nonnullarum in Dacia antiquitatum. pp. 101–2.
- Cosmo Rodewald, Money in the Age of Tiberius, Manchester University Press, 1976, p.41.
- Andrew MacKenzie, Archaeology in Romania: the mystery of the Roman occupation, Hale, 1986, p.33.
- Lica, Vasile. The Coming of Rome in the Dacian World, Universitätsverlag Konstanz, 2000, p.105.
- The Numismatist: An Illustrated Monthly Magazine for Those Interested in Coins, Medals, and Paper Money, Volume 25, 1912, p.333
- Media related to Koson at Wikimedia Commons